1PalGov © 2011

أكاديمية الحكومة اإللكترونية الفلسطينيةThe Palestinian eGovernment Academy

www.egovacademy.ps

Tutorial II: Data Integration and Open Information Systems

Dr. Mustafa Jarrar

University of Birzeit

mjarrar@birzeit.edu

www.jarrar.info

Session 15.2

RDFa

2PalGov © 2011

About

This tutorial is part of the PalGov project, funded by the TEMPUS IV program of the

Commission of the European Communities, grant agreement 511159-TEMPUS-1-

2010-1-PS-TEMPUS-JPHES. The project website: www.egovacademy.ps

University of Trento, Italy

University of Namur, Belgium

Vrije Universiteit Brussel, Belgium

TrueTrust, UK

Birzeit University, Palestine

(Coordinator )

Palestine Polytechnic University, Palestine

Palestine Technical University, PalestineUniversité de Savoie, France

Ministry of Local Government, Palestine

Ministry of Telecom and IT, Palestine

Ministry of Interior, Palestine

Project Consortium:

Coordinator:

Dr. Mustafa Jarrar

Birzeit University, P.O.Box 14- Birzeit, Palestine

Telfax:+972 2 2982935 mjarrar@birzeit.edu

3PalGov © 2011

© Copyright Notes

Everyone is encouraged to use this material, or part of it, but should

properly cite the project (logo and website), and the author of that part.

No part of this tutorial may be reproduced or modified in any form or by

any means, without prior written permission from the project, who have

the full copyrights on the material.

Attribution-NonCommercial-ShareAlike

CC-BY-NC-SA

This license lets others remix, tweak, and build upon your work non-

commercially, as long as they credit you and license their new creations

under the identical terms.

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Tutorial Map

Topic h

Session 1: XML Basics and Namespaces 3

Session 2: XML DTD’s 3

Session 3: XML Schemas 3

Session 4: Lab-XML Schemas 3

Session 5: RDF and RDFs 3

Session 6: Lab-RDF and RDFs 3

Session 7: OWL (Ontology Web Language) 3

Session 8: Lab-OWL 3

Session 9: Lab-RDF Stores -Challenges and Solutions 3

Session 10: Lab-SPARQL 3

Session 11: Lab-Oracle Semantic Technology 3

Session 12_1: The problem of Data Integration 1.5

Session 12_2: Architectural Solutions for the Integration Issues 1.5

Session 13_1: Data Schema Integration 1

Session 13_2: GAV and LAV Integration 1

Session 13_3: Data Integration and Fusion using RDF 1

Session 14: Lab-Data Integration and Fusion using RDF 3

Session 15_1: Data Web and Linked Data 1.5

Session 15_2: RDFa 1.5

Session 16: Lab-RDFa 3

Intended Learning Objectives

A: Knowledge and Understanding

2a1: Describe tree and graph data models.

2a2: Understand the notation of XML, RDF, RDFS, and OWL.

2a3: Demonstrate knowledge about querying techniques for data

models as SPARQL and XPath.

2a4: Explain the concepts of identity management and Linked data.

2a5: Demonstrate knowledge about Integration &fusion of

heterogeneous data.

B: Intellectual Skills

2b1: Represent data using tree and graph data models (XML &

RDF).

2b2: Describe data semantics using RDFS and OWL.

2b3: Manage and query data represented in RDF, XML, OWL.

2b4: Integrate and fuse heterogeneous data.

C: Professional and Practical Skills

2c1: Using Oracle Semantic Technology and/or Virtuoso to store

and query RDF stores.

D: General and Transferable Skills2d1: Working with team.

2d2: Presenting and defending ideas.

2d3: Use of creativity and innovation in problem solving.

2d4: Develop communication skills and logical reasoning abilities.

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Module ILOs

After completing this module students will be

able to:

- Demonstrate knowledge of RDFa.

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RDFa

• Bridges the gap between the Web of Documents

and the Web of Data (Web 3.0).

• Makes XHTML web pages structured data (by

embedding RDF triples inside XHTML).

• i.e., using RDFa we build small RDF graphs and

embed them inside XHTML pages.

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RDFa

• As stated by Google Webmasters guide, RDFa can be roughly viewed

as a way to label content to describe a specific type of information,

such as a restaurant review, an event, a person, or a product listing.

• These information types are called entities or items. Each entity has

a number of properties. For example, a Person has the properties

name, address, job title, company, and email address.

• In general, RDFa uses simple attributes in XHTML tags (often <span>

or <div>) to assign brief and descriptive names to entities and

properties.

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Example 1

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Example 1

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Example 2

Consider this HTML block:

<div>

My name is George Mousa. My friends call me Geno. I live in Nablus, Palestine. I work as an engineer at Birzeit University.

</div>

Annotate the HTML block above with RDFa:

<div xmlns:v="http://rdf.data-vocabulary.org/#" typeof="v:Person">

My name is <span property="v:name"> George Mousa </span>.

My friends call me <span property="v:nickname"> Geno </span>.

I live in Nablus, Palestine.

I work as an engineer at <span property="v:affiliation"> Birzeit University </span>.

</div>

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Example 2

<div xmlns:v="http://rdf.data-vocabulary.org/#" typeof="v:Person">

My name is <span property="v:name"> George Mousa </span>.

My friends call me <span property="v:nickname"> Geno </span>.

I live in Nablus, Palestine.

I work as an engineer at <span property="v:affiliation"> Birzeit University </span>. </div>

• The example begins with a namespace declaration using xmlns. This

indicates the namespace where the vocabulary is specified.

• Also on the first line, typeof="v:Person" indicates that the marked-up

content represents a Person.

• Each property of the person (such as the name and nickname) is

labeled using property.

• To indicate a URL, use rel instead of property. Consider adding the

following to our example inside the Person DIV My home page is: <a href="http://www.example.com" rel="v:url">www.example.com</a>.

• "rel" is used to convey the relationship between two entities—in this case, a

Person entity and a webpage entity.

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Example 2

• In our example, we have addressing information about George Mousa.

<div> ... I live in Nablus, Palestine. I work as an engineer ... </div>

• We use nesting. Nesting is when one information type includes the other.

• In this case, we want to include George’s Address information

(typeof="v:Address") in the typeof="v:Person“ entity.

• Here, we use rel to indicate a relationship between George (the entity v:Person)

and his address (the entity v:Address).

<div xmlns:v="http://rdf.data-vocabulary.org/#" typeof="v:Person">

My name is <span property="v:name"> George Mousa </span>.

My friends call me <span property="v:nickname"> Geno </span>.

I live in

<span rel="v:Address">

<span typeof="v:Address">

<span property="v:city">Nablus</span>,

<span property="v:country">Palestine</span>

</span>

</span>.

I work as an engineer at <span property="v:affiliation"> Birzeit University </span>.

</div>

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Let’s draw a graph of our example!

v:Person

“George Mousa”

“Geno”

v:Address

“Nablus”

“Palestine”

“George Mousa”

v:nickname

v:city

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References

• Google Webmasters Help: www.google.com/support/webmasters/

• W3C: www.w3c.org